Features: Its Lithium battery ignites powerful LED helping archers not only see your point of impact but also recover your arrow. The Spot Nock can be installed in arrows with inside diameters of .245 (S), .204(A,X), or .166(F,G). Without bushing the Spot Nock weighs 24 grains. With the or bushing it weighs 25.5 grains. With the bushing it weighs 27.5 grains. Strobe is all colors; blue/red/green.